/*
 * Copyright 2019 Immutables Authors and Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.immutables.criteria.matcher;

import org.immutables.criteria.expression.Expression;

import java.util.function.UnaryOperator;

/**
 * Matcher to group / combine statements as single unit. Similar to {@code with} statement
 * in other languages, creates an implicit context.
 *
 * <pre>
 *   {@code
 *      a.b.c.with(c -> c.isEqualTo("foo").or().isEqualTo("bar"))
 *
 *      // equivalent to
 *      a.b.c.isEqualTo("foo")
 *      .or()
 *      a.b.c.isEqualTo("bar")
 *   }
 * </pre>
 */
public interface WithMatcher<R, C> extends Matcher {

  /**
   * Group expression expressed in {@code operator} as single unit.
   * @param operator expression(s) to be grouped
   * @return new root criteria with updated expression
   */
  default R with(UnaryOperator<C> operator) {
    final CriteriaContext context = Matchers.extract(this);
    final UnaryOperator<Expression> expr = e -> Matchers.toInnerExpression(context, operator).apply(e);
    // need to add AND combiner (not DNF)
    return context.applyAndCreateRoot(expr, Combiner.and());
  }

}
